Cardioversión eléctrica transtorácica de la fibrilación auricular persistente: un dilema persistente

Atrial fibrillation (AF) is a common arrhythmia, occurring in 0.4% of the general population. AF has been shown to be associated with left atrial enlargement, which is considered both a cause and a consequence of the arrhythmia. The aim of the study was to determine the influence of AF on changes in echocardiographically determined left atrial (LA) size, during 5 year follow-up period, in a population with well-controlled hypertension, free from structural heart disease, except mild left ventricle thickening, and with an absence of other potential causes of atrial enlargement. The study group, comprised of 81 patients with persistent AF, with underlying hypertensive heart disease, consecutively referred for elective direct current cardioversion. The mean age of the study population was 59.3+/-8.4 years (ranged from 43 to 80), a mean AF duration was 8.8+/-8.7 months (ranged from 1 to 30 months). The patients underwent two-dimensional echocardiography to determine left atrial size, before and 5 years after cardioversion. Twenty out of eighty-one cardioverted patients maintained sinus rhythm 5 years after cardioversion (25%). In this group anteroposterior LA dimension and LA volume decreased from a mean (+/-S.D.) 49.7+/-4.5 to 46.8+/-4.8 mm (-6%, p < 0.05) and from 103.6+/-28.8 to 91.1+/-18.3 cm2 (-9.2%, p < 0.05), respectively. Left ventricle ejection fraction increased from 52.8+/-6.3% to 60.0+/-4.0% (p < 0.05) and clinical stage improved in patients who maintained sinus rhythm through 5 years. In contrast, in the AF group, anteroposterior LA dimension and LA volume increased from 46.6+/-4.3 to 48.1+/-5.6 mm, and from 91.3+/-20 to 103+/-34 cm2 (by an average 3.3% and 14.3%, respectively), at the end of study. When divided into two groups: Imid R:II and III NYHA class, in AF patients LA volume increased by an 21.4% in the III NYHA class and 7.3% in the Imid R:II NYHA class. Left ventricular ejection fraction did not change between the two echocardiographic studies in the AF group (44.9+/-14.3% vs. 44.6+/-12.9%, Ns). In conclusion, it has been proved that AF occurring in patients with hypertensive heart disease causes a slow and progressive increase in LA size especially in patients in functional III NYHA class, and that the maintenance of sinus rhythm partially reverts the process of LA enlargement in patients with well-controlled hypertension, a history of AF and successfully treated for AF.

Background Persistent atrial fibrillation (AF) is difficult to treat. In the absence of class I or III antiarrhythmic drugs sinus rhythm is maintained in only 30% of patients during the first year after electrical cardioversion (ECV). One of the remodeling processes induced by AF is fibrosis, which relates to inducibility and maintenance of AF. The renin-angiotensin system may play a important role in this. The aim of this study was to investigate the role of angiotensin-converting enzyme (ACE) inhibitor use on efficacy of ECV, and occurrence of subacute recurrences. Methods One hundred-seven consecutive patients with persistent AF underwent ECV. In twenty-eight (26%) patients ACE inhibitors had been started before initiation of the present episode of AF ('pre-treated' patients). Results ECV was successful in 96% of patients who were on ACE inhibitors before start of the present episode of AF compared to 80% of the patients not pre-treated (p = 0.04). After 1 month of follow-up 49% of the pre-treated patients and 50% of those not pre-treated with ACE inhibition were still in sinus rhythm (p=ns). Multivariate analysis showed that pre-treatment with ACE inhibitors and a smaller left atrial size were independent predictors of successful ECV (OR = 5.8, C.I. 1.3–26.1, and OR = 5.6, C.I. 1.2–25.3, respectively). Conclusions Pre-treatment with ACE inhibitors may improve acute success of ECV but does not prevend AF recurrences.

Background: Identification of good responders to rhythm control in the management of atrial fibrillation (AF) is worthwhile in terms of increasing hemodynamic benefit and decreasing the likelihood of unstable anticoagulation even after the Atrial Fibrillation Follow-Up Investigation of Rhythm Management. Methods: We tested the hypothesis that atrial substrate determines the risk of recurrence on rhythm control both in patients with paroxysmal AF (PAF) and in those with persistent or sustained AF (≧1 week, SAF). There were 90 consecutive patients (mean age 63 ± 12 years, 67 males and 23 females) with previous PAF (n = 66) or SAF (n = 24). They were maintained in sinus rhythm successfully for at least 1 month after conversion and then studied by transthoracic and transesophageal echocardiography. All of the patients were followed regularly by determination of symptoms, 12-lead ECG and intermittent Holter recording to determine recurrence of AF after echocardiographic study. Results: After 9.1 ± 3.8 (range 3–12) months of follow-up, 23 of the 90 (26%) patients had documented recurrence of AF (67 without recurrence). Univariate analysis of demographic characteristics, medications, ECG and echocardiographic parameters revealed that, compared with the group of patients without recurrent AF, the group of those with it included more members of the SAF group (11/27 vs. 13/67, p = 0.039), included more male subjects (22/23 vs. 45/67, p = 0.045), had a larger left atrial volume index (LAVI; 27 ± 9 vs. 22 ± 9 ml/m 2 , p = 0.024) and had lower LA appendage peak emptying velocity (LAAPEV; 42 ± 15 vs. 55 ± 22 cm/s, p = 0.01). Multivariate Cox proportional hazards regression analysis adjusted for age, gender and AF group revealed that patients with LAVI 2 and LAAPEV >46 cm/s had the least recurrence of AF (relative risk 0.18, 95% confidence interval 0.06–0.55, vs. with LAVI >30 ml/m 2 or LAAPEV 2 (log-rank p = 0.02), LAAPEV > 46 cm/s (p = 0.013) or both (p = 0.004). The superiority to predict the rate of sinus rhythm maintenance was the same in the PAF and SAF groups. Conclusions: Good responders to rhythm control in the PAF and SAF groups share the characteristics of smaller LA volume and better LAA contractile function, emphasizing the critical role of atrial substrate remodeling in recurrence of AF.